What is the basis for three days and three inspections?

"Three tests every three days" is the abbreviation of nucleic acid detection frequency in epidemic prevention and control in COVID-19. Simply put, it is to complete three nucleic acid tests within three days, and the time interval between the three nucleic acid tests shall not be less than 24 hours.

The substance of nucleic acid detection is the nucleic acid of virus. Nucleic acid detection is to determine whether COVID-19 is infected by detecting whether there is nucleic acid of foreign invasive virus in human respiratory tract samples, blood or feces. Therefore, once the nucleic acid is "positive", it can prove that there is a virus in the patient.

After COVID-19 infects the human body, it will first reproduce in the respiratory system, so we can judge whether the human body is infected with the virus by detecting the virus nucleic acid in sputum and nasopharyngeal swab. Therefore, positive nucleic acid detection can be used as a new standard for the diagnosis of novel coronavirus infection.

All living things contain nucleic acids, including DNA and RNA. Novel coronavirus is a virus containing only RNA, and the specific RNA sequence in the virus is a sign to distinguish the virus from other pathogens. After the appearance of novel coronavirus, Chinese scientists completed the analysis of the whole genome sequence of novel coronavirus in a very short time, and found the specific nucleic acid sequence in novel coronavirus by comparing with the genome sequences of other species. If novel coronavirus's specific nucleic acid sequence can be detected in patients' samples during clinical laboratory testing, it should be suggested that patients may be infected by novel coronavirus.

legal ground

Law of People's Republic of China (PRC) on the Prevention and Control of Infectious Diseases

Article 42 In the event of an outbreak or epidemic of infectious diseases, the local people's governments at or above the county level shall immediately organize forces to carry out prevention and control in accordance with the prevention and control plan and cut off the transmission route of infectious diseases. When necessary, it shall be reported to the people's government at the next higher level for decision, and the following emergency measures may be taken and announced:

(1) Restrict or stop fairs, theatrical performances or other crowd gathering activities;

(2) suspension of work, business or classes;

(three) closed or sealed public drinking water sources, food and related items contaminated by infectious disease pathogens;

(4) controlling or culling wild animals, domestic animals and poultry infected with the epidemic;

(five) closed places that may cause the spread of infectious diseases.

Article 45 In the event of an outbreak or epidemic of infectious diseases, the State Council has the right to urgently mobilize personnel or reserve materials and temporarily requisition houses, vehicles and related facilities and equipment throughout the country or across provinces, autonomous regions and municipalities directly under the Central Government.